Efficacy and safety of ustekinumab and vedolizumab in very early‐onset inflammatory bowel disease: A multicenter study from the pediatric inflammatory bowel disease Porto Group of ESPGHAN

OBJECTIVE: We aimed to assess vedolizumab and ustekinumab efficacy and safety in patients with very-early onset inflammatory bowel disease (VEO-IBD). METHODS: A retrospective study involving 29 European and North American sites affiliated with the IBD Porto Group of European Society for Paediatric Gastroenterology Hepatology and Nutrition. Clinical and laboratory data were collected from patients with VEO-IBD who commenced vedolizumab or ustekinumab before 6 years of age, between 2014 and 2024. RESULTS: Ninety-six patients (60.4% females) were included (58 ulcerative colitis, 29 Crohn's disease, and 9 IBD-Unclassified). Median (Q1-Q3) age at diagnosis was 2.3 (0.4-4.2) years, 37 (38.5%) patients were diagnosed at age <2 years old. Thirty-seven (38.5%) patients received ustekinumab, 67 (69.7%) vedolizumab, and 11 (11.5%) both drugs. Median (Q1-Q3) follow-up time was 11 (6-26) and 14 (7-39) months for ustekinumab and vedolizumab, respectively. Eighty (84.2%) patients were previously treated with infliximab, 23 (24.2%) with adalimumab, and 20 (20.8%) with both. The median (Q1-Q3) time from diagnosis to vedolizumab and ustekinumab initiation was 15 (9-26) and 20 (11-36) months, respectively. Ustekinumab-treated patients achieved clinical remission in 24.3%, 51.4%, and 40.5% at end of induction, week 26, and week 52, with steroid-free remission in 18.9%, 45.9%, and 35.3%, respectively. Vedolizumab-treated patients achieved clinical remission in 29%, 47.5%, and 40.3%, with steroid-free clinical remission (SFCR) rates of 10.4%, 43.3%, and 37.3% at the same time points. Infectious adverse events were reported in 3 (8.3%) of ustekinumab-treated and 5 (7.6%) vedolizumab-treated patients, none severe. CONCLUSIONS: Ustekinumab and vedolizumab demonstrated high therapeutic durability in patients with VEO-IBD; 1-year rates of SFCR were modest.